1. Field of the Invention
This invention relates to simulated roofing shingles and, more particularly, an improved interlocking simulated shingle construction made from recycled materials.
2. Background Art
For many years wood, shingle, shake, and ceramic or clay tile roofing has been used for the obvious purpose of sealing construction against rain and other weather elements. With shake shingles, in particular, their rough appearance forms pleasing patterns that give them considerable decorative appeal and have become the standard and required roofing material in many residential areas. However, in time wood, typically cedar, shakes deteriorate because of insect infestation, rotting, splitting, cracking, warping, thermal expansion and absorption of moisture, thereby decreasing their usefulness and decorative aspects. In addition, the cost of cedar shakes has substantially increased.
Various types of simulated shingles have been taught and patented as substitutes for wood shakes. In many cases, they do not provide the decorative appearance of shingle or shake configurations. For instance, composite materials of high or low density polyethylene, (HDPE) and (LDPE) and fibers respectfully, have been taught in U.S. Pat. Nos. 5,088,910 and 5,096,046. These teachings require extensive and uncommon equipment to create such synthetic wood products. The problems with wooden shake shingles, in addition to the problem of diminishing forest supply of cedar shakes, has led to other synthetic materials such as cement, asbestos composition, fiberglass, aluminum, galvanized steel and sophisticated expensive engineered thermoplastics. In many cases, weathering and age of these materials causes them to lose their simulated and decorative design concepts and become unsightly and discolored. Many commercially available products are paneled designs repeating the decorative surface over a large area, as for example, 4'.times.8', but still do not provide the simulated decorative effect demanded by home owners and constructions using shakes. One of the negative aspects of composites is that they fail to exhibit the reinforcing potential of wood fibers, and/or other fibers, and, in many cases, a poor adhesion between the fibers and the matrix, especially in the use HDPE.
Another facet of the times is the generation of solid and industrial waste. The creation of the United States Environmental Protection Agency (EPA) is concerned with the continued discarding of waste which is capable of but has not been recycled. Especially is this so with plastics. Production of plastics in the United States is increasing and is expected to and already has become a considerable part of the waste stream product. The use of recycled plastics as a part of composite materials is limited largely because of the competition with virgin resins and the public misconception that they are inferior if recycled. Beyond the concern of increasing waste plastic products from consumers is the waste from original manufacturers of plastic products. Many of these plastics such as PVC, being thermoplastic, can be remelted repeatedly. Approximately 40% of PVC produced is directed to pipe and tubing and growing 8% per year.
The term "shake" is commonly used and recognized in the roofing industry for wooden shake, shingles, slate or tile members.